177,066 research outputs found
INSTRUMENTS AND METHODOLOGIES FOR THE UNDERWATER TRIDIMENSIONAL DIGITIZATION AND DATA MUSEALIZATION
No full textIn the research started within the SINAPSIS project of the Università degli Studi Suor Orsola Benincasa an underwater stereoscopic scanning aimed at surveying of submerged archaeological sites, integrable to standard systems for geomorphological detection of the coast, has been developed. The project involves the construction of hardware consisting of an aluminum frame supporting a pair of GoPro Hero Black Edition cameras and software for the production of point clouds and the initial processing of data.
The software has features for stereoscopic vision system calibration, reduction of noise and the of distortion of underwater captured images, searching for corresponding points of stereoscopic images using stereo-matching algorithms (dense and sparse), for points cloud generating and filtering.
Only after various calibration and survey tests carried out during the excavations envisaged in the project, the mastery of methods for an efficient acquisition of data has been achieved.
The current development of the system has allowed generation of portions of digital models of real submerged scenes. A semi-automatic procedure for global registration of partial models is under development as a useful aid for the study and musealization of sites
Compressed Sensing: a new framework for signals recovery and its application in Digital Holography
No full textIn olografia digitale l'informazione di ampiezza e fase del fronte d'onda di un oggetto può essere ottenuta quantitativamente e analizzata in digitale attraverso la simulazione numerica delle leggi di diffrazione. Partendo da questo, sono state realizzate molte applicazioni di grande interesse in campo ottico, come l'imaging microscopico a contrasto di fase, la recognition di oggetti 3D e il display dinamico di ologrammi in 3D. In ogni caso, la qualità di queste elaborazioni dipende fortemente dalla qualità degli ologrammi da processare, in particolare dipende dal rumore che il processo di acquisizione di un ologramma introduce sul fronte d'onda registrato.
Le tecniche che vengono, attualmente, applicate sugli ologrammi e sulle loro ricostruzioni numeriche per ottimizzarne la qualità, sono tipiche dell'image processing. Molte di esse permettono di ridurre o sopprimere il rumore, che nel caso specifico di ologrammi digitali, è composto da una mistura di due componenti: un rumore additivo Gaussiano, non correlato all'ologramma, e un rumore moltiplicativo di tipo speckle. Ad esempio i metodi classici basati su trasformata di Fourier e trasformata wavelet sono stati ampiamente studiati, ma possono essere applicati solo nei rispettivi domini trasformati. Inoltre, tali metodi sono fortemente influenzati dal cambiamento di alcuni parametri del fronte d'onda da elaborare, come ad esempio la frequenza, l'ampiezza etc. Al fine di superare efficacemente i limiti evidenziati da i più comuni algoritmi di denoising, risulta fondamentale la realizzazione di algoritmi di ricostruzione che siano robusti nelle diverse condizioni in cui un ologramma può essere acquisito. A tal fine, questo lavoro di tesi propone un nuovo metodo di denoising per ologrammi digitali, molto robusto ed efficiente, basato sulla tecnica del Compressed Sensing (CS).
Il CS è una procedura per l'acquisizione e ricostruzione di segnali che possono essere rappresentati in forma sparsa in un opportuno dominio trasformato. Dopo un inizio lento, questo tema ha acquisito un'elevata risonanza, ed attualmente, ha un impatto scientifico molto forte grazie al riconoscimento che, in natura, molti segnali, se proiettati in un opportuno dominio, ammettono una rappresentazione sparsa. Sfruttando questa sparsità, si può ottenere una migliore approssimazione della funzione distorsione-tasso di un segnale, e fornire linee guida per realizzare un’efficiente ed efficace fase acquisizione e di denoising del segnale, come verrà dimostrato in questa tesi. Nonostante il grande impatto che questo framework ha avuto nella comunità scientifica, la chiave per una comprensione più profonda di questa tecnica è l'identificazione dei limiti fondamentali nei processi di ricostruzione e denoising.
Questa tesi si propone di analizzare questi aspetti per segnali particolari, quali sono gli ologrammi digitali, fornendo una procedura standard per un’efficiente ricostruzione numerica a valle di un processing mirato all'eliminazione delle componenti di rumore. L'algoritmo di denoising progettato ed implementato, risulta molto efficace e robusto nella rimozione del rumore che corrompe gli ologrammi digitali, come dimostrano da diversi esempi sperimentali. Infatti il metodo è stato testato per diversi ologrammi, acquisiti in diverse condizioni sperimentali, ed in ogni caso i risultati si sono rivelati eccellenti, il che dimostra la bontà e la robustezza del metodo proposto. Inoltre è stato analizzato l'effetto di denosing attraverso la proiezione degli ologrammi processati, per vedere e quantificare i miglioramenti che questa tecnica produce nel display 3D di ologrammi
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Letter from R. R. Zellick, Assistant Trust Officer, Anglo California National Bank of San Francisco, to Joseph R. Goodman, October 2, 1942
No full textLetter from R. R. Zellick, Assistant Trust Officer at The Anglo California National Bank of San Francisco, to Joseph R. Goodman, regarding property owned by Dave Tatsuno. Zellick mentions a dispute between current tenants and Tatsuno, and that Tatsuno has asked Goodman to help locate trustworthy tenants.Personal correspondence, organizational records, government documents, publications, and other papers created or collected by Joseph R. Goodman documenting the forced removal and incarceration of Japanese Americans during World War II, as well as organized resistance to incarceration. Included in the collection are records of the Japanese Young Men's Christian Association and the Japanese American Citizens' League in San Francisco, including papers of the Japanese YMCA's executive secretary Lincoln Kanai; Sakai family papers; Goodman's correspondence to and from Japanese American incarcerees, organizations opposing forced removal and incarceration of Japanese Americans, the War Relocation Authority, and others; publications, photographs, and ephemera from the Topaz Relocation Center, where Goodman taught high school; War Relocation Authority records and publications; and newspaper clippings, pamphlets, and reports about forced removal and incarceration created by various government, religious, and civic organizations, in California and nationwide
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Liftings for noncomplete probability spaces
No full textThe current state of knowledge concerning liftings for noncomplete probability spaces is discussed. This is a somewhat expanded version of the author's talk given at the 1991 Summer Conference on General Topology and Applications in Honor of Mary Ellen Rudin and Her Work.PT: S; CR: BURKE MR, IN PRESS P AM MATH S BURKE MR, 1991, ISRAEL J MATH, V73, P33 BURKE MR, 1992, ISRAEL J MATH, V79, P289 CARLSON T, THEOREM LIFTING CHRISTENSEN JPR, 1974, TOPOLOGY BOREL STRUC FREMLIN DH, 1989, HDB BOOLEAN ALGEBRAS, P877 INOESCUTULCEA A, 1966, 5TH P BERK S MATH ST, V2 IONESCUTULCEA A, 1967, CONTRIBUTIONS PROB 1, P63 IONESCUTULCEA A, 1969, TOPICS THEORY LIFTIN JECH TJ, 1978, SET THEORY JOHNSON RA, 1980, P AM MATH SOC, V80, P234 JUST W, IN PRESS T AM MATH S KUPKA J, 1983, INDIANA U MATH J, V32, P717 LOSERT V, 1983, LNM, V1080, P95 MAHARAM D, 1958, P AM MATH SOC, V9, P987 SHELAH S, 1983, ISRAEL J MATH, V45, P90 TALAGRAND M, 1982, P AM MATH SOC, V84, P379 VONNEUMANN J, 1931, CRELLES J MATH, V165, P109; NR: 18; TC: 0; J9: ANN N Y ACAD SCI; PG: 4; GA: BZ86BSource type: Electronic(1
Hansen, Lee (Lee R.). Union, non-union, and managerial pay plan state employees, 2008-2019
No full text1 online resource (2 pages)"July 1, 2021."Provides the number of union and non-union state employees in each of the last 14 years. Also provides the number of state employees paid under the state's managerial pay plan during each of those years. Updates OLR research report 2019-R-011
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